The present invention relates to an electromagnetic valve. More specifically, the present invention relates to an electromagnetic valve which can perform switching between supply and exhaust of a fluid to and from an air mat M or the like, or which can perform switching supply of a fluid to an air mat divided into a plurality of zones.
As shown in FIG. 23, one of the conventional electromagnetic valves comprises an electromagnet 100, an internal cylinder 101 which has a bottom and is inserted into the electromagnet 100, a movable valve member 103 which is provided inside the internal cylinder 101 and supported by a spring 102, and a casing 106 which is attached to the end surfaces of the electromagnet 100 and includes an air supply passage 104 and an air exhaust passage 105. According to this electromagnetic valve, when the electromagnet 100 is not electrified, a valve disc 107 is pressed against a valve seat 108 by the force of the spring 102, so as to block the flow of air. On the other hand, when the electromagnet 100 is electrified, the attraction of the electromagnet 100 makes the movable valve 103 move against the spring 102 to allow the valve disc 107 be moved away from the valve seat 108, so that air can be supplied.
However, in order to supply and exhaust air, this electromagnetic valve requires an adapter which performs switching between the passages to exhaust air. Furthermore, in order to switch the supply of a fluid to an air mat which is divided into a plurality of zones, two sets of such electromagnetic valve and additional adapter for combining them is needed. As a result, there are problems that the structure is complicated, the production cost is increased, and the operability is deteriorated.
In view of these circumstances, the present invention has an object of providing an electromagnet valve whose production cost is inexpensive and which can perform switching among various passages for a fluid.